High-pressure contact switch



Nov. 2, 1948. H. w. GR AYBILL HIGH PRESSURE counc'r swn'cn 2 Sheets-Sheet 1 Filed Jan. 10. 1945 I IN V EN TO R Hdn qrd/L/Grayb/M wysszs;

ATTORNE Nov. 2 1948. H. w. GRAYBILL HIGH PRESSURE GON'I'AG'JI' SWITCH Filed 1945 w b Rm v m6 .M .0 N. R n w .m ,0. 2 J Ma my 08 H Patented Nov. 2, 1948 UNITED STATES PATENT lorries HIGH-PRESSURE CONTACT SWITCH Howard W. Grayblll, Pittsburgh, Pa., aslignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application January 10, 1945, serial No. 512,183

10 Claims.

issued as Patent No. 2,363,360, November 21, 1944,

and assigned to the same asslgnee as this invention. This switch is oi. the type wherein a switch blade is mounted on or adjacent one line terminal for pivotal movement about a transverse axis to and away from a position where it is disposed in proximity to a line contact, and the blade is also mounted for rotation about its longitudinal axis when in proximity to the line contact, to move into and out of high pressure engagement with the line contact. Various means have been proposed for conducting current to the blade from the line terminal at its mounting, such as flexible shunts, or a duplicate line contact as in the Rawlins application. Because the pivotal mounting of the blade includes relatively rigid parts, it has not heretofore been possible to conduct current through the pivot 30 parts because high pressure contact of these parts could not be obtained. One mode of providing a conducting path through the blade pivot parts is disclosedand claimed in myv copending application Serial No. 513,852, filed December 11, 1943, now Patent No. 2,436,296, issued February 17, 94-8, to the same assignee as this invention.

One object of this invention is to provide in a switch, novel means for conducting current from the switch blade to the line terminal adjacent the blade pivot embodying high pressure contacting portions.

Another object of this invention is to provide a plurality of novel high pressure, limited area contact portions between relatively movable electrical conducting members having relatively rigid connecting portions. v

Another object of this invention is to provide a novel self-aligning pivotal mounting for a switch blade having relatively rigid mounting parts.

Another object of this invention is simply to provide a novel high pressure, limited area contacting arrangement for relatively movable elecr trical conducting parts.

Another object of this invention is to provide a novel self-aligning, high pressure, limited area contacting arrangement for relatively movably mounted electrical conducting parts.

These and other objects of this invention will become more apparent upon consideration of the following detailed description oi a preferred embodiment thereof. when takenin connection with the attached drawings, in which:

Figure 1 is a side elevational view of a disconnecting switch constructed in accordance with this invention:

Fig.2 is a top plan view of the switch shown in Fig. 1;

the switch shown in Fig. 1, taken substantially on the line III-III thereof; and Fig. 4 is also an enlarged transverse section through the switch shown in Fig. 1, but taken substantially on the line IV-IV thereof.

The particular switch illustrated may be mounted on a supporting base 2, such as a channel iron or the like, and includes spaced insulators l and 8 rigidly secured to spaced'mounting 0 on support 2,- for example as by bolts Ill. The insulator 4 has secured to the free end thereof a terminal strap i2 of copper or other good electrical conducting material, for example as by bolts II. The terminal strap i2 has one end thereof angularly directed as at It in a direction outwardly of insulator l, to form a stop flange, -for a purpose to be described. A generally U-shaped line contact 18, preferably of some wear resistant good electrical conducting material, such as copper alloy, for example a beryllium-cobalt-copp'er alloy, is adapted to be secured on terminal strap i2 in electrical conducting relation therewith, by bolts l4 and 20 extending through apertures provided in the bight portion A of the contact. One of the securing bolts it also acts to secure an arcing horn 22 inconducting relation to terminal strap l2. The outer end of arcing horn 22 is bent at an angle as shown at 24.

As clearly shown in Figs. 1 and 2, terminal strap 12, at the end opposite stop flange ll, extends outwardly of insulator 4 for the connection ofa line conductor thereto. An operating insulator 26 is provided a s end with a short stub shaft ill, adapted to 'b 7 tatably mounted in a bearing 28 mounted'on support 2. An operating crank 32, which may be connected to suitable operatingmechanism, or directly actuated manually, ii desired, is secured to stub shaft 30 and insulator-2810i actuating the insulator. A supporting or bracing Fig. 3 is an enlarged transverse section through,

- frame 34 is adapted to be secured to the outer thereto. Frame 34 may be of any desired metallic material and is preferably cast to provide opposite side plates 35, and integral open webbing .31 joining the side plates at selected points, with reinforcing flanges 39 positioned adjacent the end of frame 34 nearest to rotatable insulator 28. The ends 38 of the sides of frame 34 are extended to be substantially in alignment with the axis of rotation of insulator 25, and are transversely apertured for cooperation with integral lugs 49 provided on a hollow blade supporting housing 42.

It will be seen by reference to Figs. 2 and 4, that lugs 49 on blade supporting housing 42 are each provided with a conically shaped recess 43 terminating in a recess 44 which is reduced in size. The ends of extensions 38 of frame 34 are each provided with threaded openings for receiving threaded bearing pins 45 having generally spherically shaped inner ends 46 with a projection 41 of reduced size projecting therefrom. Each bearing pin 45 is adapted to be threaded into the respective extensions 38 with the spherical portions 48 thereof engaging the conically shaped openings 43 of lugs 40. Bearing pins 45 are tightened in place so that extensions 38 are separated a slight amount within their elastic limit, to obtain a contact pressure between bearing pins 45 and lugs 40 on the order of 100 to 300 pounds. It will be noted that this pressure will be subjected over a contact surface between bearing pins 45 and lugs approximately an annular line, due to the spherical configuration of the end of bearing pin 45 and the conical configuration of the outer end 43 of the recess in lugs 48. Furthermore, this pivot mounting of housing 42 is self-aligning due to the fact that lugs 40 may sit on thespherical end 48 of the bearing pins at any angle. Since no part of the contacting surfaces of lugs 40 and bearing pins 45 is ever exposed to the atmosphere, oxidation of these surfaces is prevented. In order to secure bearing pins 45 at the axial position to which they have been adjusted, lock nuts 48 may be provided, and it is preferred that a positive locking means such as lock washers 49 be employed. Each lock washer 49 is provided with an inwardly extending key projection 53 adapted to be received in a key slot provided in the outer end of each bearing pin to prevent relative rotation of the washer and pin. Washers 49 are provided about the periphery thereof with a plurality of notches 55 in any one of which a lock screw 50 may be received.

In assembling lock washers 49, after bearin pins 45 have been adjusted axially to obtain the desired contact pressure on lugs 40, the lock washers 49 are slipped over the outer ends of the bearing pins and lock screws 50 are screwed nto tapped openings in extensions 38, with the head of each screw 50 being received in whichever peripheral indentation of its lock washer 49 coincides with the tapped opening in its extension 38. It is apparent that since screw 50 prevents rotation of washer 49 relative to supporting frame 34, and key projection 53 prevents relative rotation of the washer and its bearing pin 45, that rotation of the bearing pin is thereby prevented and consequently uniform cont-ac pressure is maintained.

The switch blade 52 proper, is preferably tu bular in form and the inner end thereof extends 4 through an opening provided in hollow blade support 42, and is provided within ',the blade support with an actuating fork 54 secured to the inner end of the blade, Switch blade 52 is rotatably mounted in one wall of blade housing 42 and in an outer wall defining the outer end of a hood portion 80 integral with the blade housing 42, so that the blade may be rotated substantially about its own longitudinal axis. An angularly extending drive crank 56 is provided for the purpose of actuating blade 52 both in a rotatable fashion about its longitudinal axis, and in a pivotal manner about bearing pins 45 for blade support housing 42. The drive crank 56 is in- 'tegral with a cap plate 51 secured to the free end of rotatable insulator 26, for example as by bolts 58. The portion of the actuating crank structure adjacent plate 51 is provided with a slot 60 for receiving an integral projection 52 on frame 34. A pivot pin 64 is adapted to be freely positioned through apertures provided in the drive crank structure including its cap plate 51, and through an aperture provided in frame extension 52. Frame 34 thus provides a bearing for the free end of rotatable insulator 26 which also acts to brace the insulator at its outer end.

Rotatable drive crank structure 56 is'provided with a substantially spherical portion 66 adapted to be positioned at the point where the drive crank structure passes through an opening 58 provided in the blade supporting housing 42.

, formed on the inner wall of blade supporting housing 42, as in the aforementioned Rawlins patent.

The outer end of switch blade 52 is flattened at 14 to form a portion having a width somewhat greater than the space between the sides of contact i8, so that when positioned transversely of contact i8,.sideedge portions of blade part 1 will be in high-pressure wedging engagement with contact l8. Preferably, an arc and wear resistant U-shaped contact piece 15 is provided for the end 14 of the blade, with the contact piece having the leg portions thereof telescoped over the side edges of part 14 of the blade, and

preferably being channel-shaped in section so,

as to receive such edges within the leg portions of the contact strip 15. The contact strip 15 may be secured to the outer end of the blade in any desired manner, such for example as by soldering the leg portions thereof to the side edges of the blade. Preferably, U-shaped contact strip 15 is secured to blade end 14 with the housing 42 is provided with a cover 82 for the open side thereof, to completely enclose the space beneath hood portion 80 and the portion of switch blade 52 which lies therein. Cover 82 may be secured in position by any desired means,

' such, for example, as by screws 84. Hood portion is provided beneath the same with an integral longitudinally extending contact supporting flange 86 adapted to support a generally U- shaped contact'strip 81 of a good electrically conducting material, such, for example, as copper or the like, and a similarly shaped contact spring 88, by means of a securing nut 90. The ends of I! where it passes through hood portion 80, to

engage the opposite sides of this portion of the blade under pressure exerted by spring II.

In the closed circuit position of the switch. the parts occupy the positions shown in the draw- ,ings, that is, blade portion 14 is positioned substantially transversely of the sides of line contact I8 so as to be in high pressure engagement therewith. Inasmuch as contact 81 beneath hood portion 80 engages a cylindrical surface of the switch blade under pressure, and bearing pins 45 similarly engage lugs 40 on blade supporting housing 42 under pressure, the electrical circuit through the switch may be traced from terminal strap I! to line contact i8, and then to switch blade 52 by the high pressure engagement of the line contact I 8 with contact strip II on the blade; the circuit proceeds through the switch blade to contact strip 81 and through blade supporting housing 42 and its lugs 40 to extensions I8 of frame 34 by virtue of the high pressure engagement oi bearing pins 45 with lugs 40; then through the frame to the other line terminal I].

In the operation of the switch'described above,

when it is desired to open the switch, insulator 26 is rotated in a counterclockwise direction, as viewed in Fig. 2. The initial movement of the rotatable insulator causes drive crank 68 to carry actuating fork B4 of the blade with it and thereby cause rotation of the blade about its longitudinal axis to position portion 14 of the blade at an acute angle with respect to contact l8. During this rotation of blade '52, contact" remains in pressure engagement with the portion of the blade beneath hood 80. and there is no pivotal movement about bearing pins 45, because the roller 10 on the actuating crank travels in the straight end portion 69 of slot I2 disposed in the plane of this initial movement of roller 10. However, after contact pressure has been released at line contact I8, the roller will enter the inclined portion of slot 12 and thereby cause movement of blade supporting housing 42 and with the blade 52, in a clockwise direction as viewed in Fig. l, to move the blade to a position spaced away from line contact II. The open position of the switch blade may be defined by an adjustable stop bolt I3 mounted in frame 84 in a position to be engageable with an identation Ii provided in blade supporting housing 42. During pivotal movement of blade 52 away from contact l8, actuating crank 56 has but a small component of motion transversely of fork 54, and hence very little rotation of the blade about its longitudinal axis will occur. When it is desired to close the circuit, insulator 26 is rotated in the opposite direction. This first causes pivotal movement of the blade and its blade support about bearing pins 45, until the outer end of the blade enters contact l8. At this time, roller 10 on the actuating crank will be just entering the straight end portion 69 of slot 12 in the housing, so that continued rotation of insulator 28 in the same direction will not cause any further pivotal movement of the blade and its housing about bearing pins 45, but will'only cause rotation of blade 52 about its longitudinal axis to cause the portion I4 to be rotated into high pressure contact with line contact ll. During pivotal movement of blade 52 adjacent line contact i8, arcing horn 18 thereon will remain in engagement with fixed arcing horn 22. Stop flange l8 prevents excessive movement of blade I! when the closing operation occurs rapidly.

From the foregoing it is believed apparent that this inventionprovides a novel arrangement for conducting current from one line terminal 33, to

switch blade 52. It will be observed that this current path includes high pressure limited area contact between lugs 40 and bearing pins mounted in frame extensions 38, which contact is maintained at all positions of the switch, and which provides a self-aligning bearing for pivotal mounting of the switch blade. This current path to blade 52 also includes high pressure contact strip 81 likewise in continuous engagement with blade 52, and protected from the atmosphere by being enclosed beneath hood portion 80. Inasmuch as the contacting surfaces of bearing pins 45 and lugs are not exposed to the atmosphere, the entire current path from terminal 33 tothe switch blade is entirely protected at all times. The particular means for conducting current from the blade to its supporting housing and from the supporting housing to frame 34, while especially adapted for the particular switch construction illustrated, may find certain desirable cooperation in other types of switches, or even for conducdng current between relatively movable electrical conducting membersother than switches.

Having described a preferred embodiment of the invention in accordance with the patent statutes, it is desired that the invention be not limited to this particular embodiment, inasmuch as it will be obvious, particularly to persons skilled in the art that many changes and modifications may be made in this particular structure without departing from the broad spirit and scope of this invention as set forth in thefollowing claims;

I claim as my invention: 1. In a switch of the type having a switch blade movably mounted on substantially its longi tudinal axis on a blade support, which in turn is pivotally mounted on.a line terminal for movement of said blade to and away from a position in proximity with a line contact spaced from said line terminal, and actuating means operable in a circuit opening operation to first move said blade relative to said support out of high pressure engagement with said line contact and to thereafter pivotally move said blade to a position spaced away from said line contact, the combination of means for conducting current from said line terminal to said blade comprising permanent low resistance connections between said blade and blade support, and between said blade support and line terminal, the connection and pivotal mounting of said blade support and terminal comprising rigid portions spaced apart a fixed distance, on one member for receiving therebetween another rigid portion on the other member, pivot means mounted on each of said spaced portions to be engageable with pivot means at eachside of said other rigid portion, said pivot means comprising at least one bearing member mounted for adjustment along the pivot axis on one of said members and having a contact surface engageable with a contact surface on the other of said members, and said contact surfaces being configurated so as to engage only substantially on an annular line.

2. In a switch of the type having a switch blade movably mounted on substantially its longitudinal axis on a blade support, which in turn is pivotally mounted on a line terminal for movement of said blade to and away from a position in proximity with aline contact spaced from said line terminal, and actuating means operable in 'a' circuit opening operation to first move said blade relative to said support out of high pressure en agement with said line contact and to thereaf er pivotally move said blade to a position spaced away from said line contact, the combination of means for conducting current from said line terminal to said blade comprising permanent low resistance connections between said blade and blade support, and between said blade support and line terminal, the connection and pivotal mounting of said blade support and terminal comprising rigid portions spaced apart a fixed distance on one member for receiving therebetween another rigid portion on the other member, pivot means mounted on each of said spaced portions to be engageable with pivot means at each side of said other rigid portion, said pivot means comprising at least one bearing member mounted for adjustment along the pivot axis on one of said members and having a contact surface engageable with a contact surface on the other of said members, said contact surfaces being configurated so as to engage only substantially on an annular line, and means for locking said pivot means against movement after adjustment in a direction to cause engagement of said contact surfaces under high pressure.

3. In a switch, a terminal supporting member, a .switch blade member, one of said members having relatively rigid portions spaced apart a fixed distance for receiving arigid part of the other member therebetween, pivot means mountcd for adjustment along the pivot axis on each of said spaced apart portions and having a contact surface positioned to engage a contact surface on said other member, and said contact surfaces being conflgurated so as to engage only substantially on an annular line.

4. In a switch, a terminal supporting member, a switch blade member, one of said members having relatively rigid portions spaced apart a fixed distanceforreceiving a rigid part of the other member therebetween, pivot means mounted for adjustment along the pivot axis on each of said spaced apart portions and having a contact surface positioned to engage a contact surface on said other member, said contact surfaces being configurated so as to engage only substantially on an annular line, and means for locking said pivot means against movement after adjustment in a direction to cause engagement of said contact surfaces under high pressure.

5. In a switch, a terminal supporting member, a switch blade member, one oi said members having relatively rigid portions spaced apart a fixed distance for receiving a rigid part of the other member therebetween, pivot means mounted for adjustment along the pivot axis on each of said spaced apart portions and having a contact surface positioned to engage a contact surface on said other member, said contact surfaces having substantially spherical and conical interiitting configuration so as to be engageable only along substantially an annular line and so as to be selfaligning.

6. In a device of the type described, relatively movable conducting members one which has rigid spaced apart portions for receiving a rigid portion of the other member, means pivotally connecting said portions of said members comprising bearing members mounted for adjustment to different fixed positions along the pivot-axis on one member and having contact surfaces at one end thereof so as to be adjustable to engage cooperating contact surfaces on the other member under pressure.

7. In a device of the type described, relatively movable conducting members one which has rigid spaced apart portions for receiving a rigid portion of the other member, means pivotally connecting said portions of said members comprising bearing members mounted for adjustment along the pivot axis on one member and having contact surfaces at an end thereof so as to be adjustable to engage cooperating contact surfaces on the other member under pressure, and means for locking said pivot means against movement after adjustment -in a direction to cause engagement of said contact surfaces under high pressure.

8. In a switch, spaced line terminals, a switch blade adapted to be mounted on one of said terminals for rotative movement substantially about 'its longitudinal axis into and out of high pressure engagement with acontact on the other of said terminals, and for pivotal movement to and away from a position adjacent said contact, a rigid member of conducting material pivotally movable with said blade but not rotatable therewith about its longitudinal axis, said rigid mem ber having one contact portion positioned to engage contact means on said blade at all positions of said blade, said member having another contact portion positioned to engage contact means on said one line terminal at all positions of said blade, the engaging portions of said contact portions and contact means being limited in area, and said rigid member having housing means movable therewith and entirely enclosing the contact means on said blade and its cooperating contact portion at all positions of said blade.

9. In a switch, spaced line terminals, a switch blade adapted to be mounted on one of said terminals for rotative movement substantially about its longitudinal axis into and out of high pressure engagement with a contact on the other of said terminals, and for pivotal movement to and away from a position adjacent said contact, a rigid member of conducting material pivotally movable with said blade but not rotatable therewith about its longitudinal axis, said rigid memher having one contact portion adapted to engage contact means on said blade at all positions of said blade, said member having another contact portion positioned to engage contact means on said one line terminal at all positions of said blade, the engaging portions of said contact portions and contact means being limited in area, and means causing said contact portions to engage said contact means under pressure at all times.

10. In a switch, spaced line terminals, a switch blade adapted to be mounted on one of said terminals for rotative movement substantially about its longitudinal axis into and out of high pressure engagement with a contact on the other of said terminals, and for pivotal movement to and away from a positionadjacent said contact, a rigid member of conducting material, and said rigid member having housing means movable therewith and entirely enclosing the contact means on said blade and its cooperating contact portion at all positions of said blade having one contact portion positioned to engage contact means on said blade at all positions of said blade, said rigid member having another contact'portlon positioned to engage contact means on said one line terminal and including contact parts c0- axial with the respective axes of relative movement of said rigid member with respect to said blade and line terminal, respectively, so as to be engaged ht all positions of said switch, and means causing said contacting parts to engage under pressure at all Number I 2,039,059 1 2,06 ,65 HOWARD w. GRAYBILL- 5 2,141,842

REFERE CES, cum) 2,179,539

The following references are of record in the file or this patent:

Rawllns Nov. 21, 1944 3 Certificate of Correction Patent No. 2,453,011

= HOWARD W. GRAYBILL It isl ereby certified that errors appear in the printed specification of the above numbered patent requiring correction as follows:

Column 8, line 63, beginning with the comma and Words and said strike out all to and including blade,before having in line 67, and insert instead piootally movable with said blade but not rotatable therewith about its longitudinal axis, said rigid member; i u and that the said Letters Patent should be readavith these corrections therein that the same may conform to the record of the casein the Patent Ofiice.

Signed and sealed this 17th day of January, A. D. 1950.

THOMAS F. MURPHY,

Assistant Commissioner of Patents.

November 2, 1948 a 

